The present invention relates to an apparatus for forming a carton for use as a container for liquids such as cow's milk, fruit juice or the like. The apparatus also fills the carton with the liquid, and forms and seals the carton top. More particularly, the present invention presents a device for shifting carton blanks with bottoms that are sealed in the above-mentioned apparatus, to a bucket conveyor, with disclosure of construction of the bucket conveyor, construction of a folding device for shaping the top of the carton that is filled with the liquid and the construction of a device for treating the triangular projection (lug) formed when the carton top is formed into a flat shape.
The apparatus for forming the carton, filling the carton, forming the carton top and sealing the same will be generally referred to as an "automatic carton packing machine", hereinafter. The automatic carton packing machine is required to fulfill various requirements such as high treating capacity (yield), compactness, and so forth. In addition, the automatic packing machine is required for processing of cartons irrespective of their shape.
In a conventional automatic carton packing machine, carton blanks with sealed bottoms are placed in a frame of a chain conveyor one by one, and a series of operations such as filling of cartons with the liquid, formation of the carton top and sealing of the same are performed while the carton blanks are conveyed by the chain conveyor. Therefore, there is a practical limit in the speed of operation. Particularly, the step shifting of the carton blanks with sealed bottoms to the frame of the chain conveyor, after withdrawal of the same from the mandrel, is made at an extremely low efficiency which inconveniently limits the efficiency of the work.
Turning to FIG. 1A to FIG. 1F and FIG. 2A to FIG. 2F, there are two types of foldings of carton tops after filling thereof with liquid: namely a flat top as shown in FIGS. 1A to 1F and gable top as shown in FIGS. 2A to 2F. Hitherto, these shapes of the carton tops were formed by different folding devices. In other words, for obtaining both of these two types of the carton tops, it has been necessary to employ two different devices. In the case of the flat carton top as shown in FIG. 1F, triangular projections or lugs are formed at each side of the carton top. It is necessary to fold these lugs down onto both side surfaces of the carton, because such lugs will otherwise hinder the transportation, storage and display of the cartons. To this end, it has been necessary to employ a suitable measure or arrangement such as provision of an elongated guide in the direction of running of the chain conveyor, to fold down the lugs toward the side surfaces of the carton. This requires, however, an impractically long length of the machine as a whole.